A lossless compressions scheme most widely used in recent is JPEG-LS. However, the JPEG-LS is selected and adopted by considering a processing speed, not considering a maximum compression ratio.
The JPEG-LS standard is defined in 2000. At that time, the JPEG-LS technique is efficient in view of the processing speed of H/W. These days, the speed of the H/W is increased greatly and an image used is changed to a high-quality high-definition image. Accordingly, conventional algorithms are not efficient any more.
Hence, an appropriate scheme to design the H/W with the higher compression ratio was developed by researching a method for the higher compression ratio and adding new algorithms for a lossless method applicable to a video and a still image and a compression method for a high definition image.
As a variety of multimedia devices are released, terminal with a higher resolution are demanded. To respond to this, MPEG which is ISO/IEC JTC 1 SC29WG11 and ITU-T SC16 Q9 VCEG are also working on standardization of an image compression scheme for supporting an ultra-high definition, such as High-performance Video Coding (HVC)/Next Generation Video Coding (NGVC) supporting 4K or more resolutions, so as to accommodate the demands in many industries. Future trends of the multimedia devices are to support the ultra-high definition.
However, the image compression standardized by the MPEG and the VCEG takes account of loss to compress a large amount of data, and suffers from considerable complexity. In this regard, a method for the lossless image compression with low complexity is needed.